Apparatus for excavating tunnels



March 18, 1969 R. w. ENZ 3,433,532

APPARATUS FOR EXOAVATING TUNNELS Filed June 12, 1967 Sheet of w w W n? '9 R b w INVENTOR.

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March 18, 1969 I R. w. ENZ

APPARATUS FOR EXCAVATING TUNNELS Filed June 12, 1967 Sheet INVENTOR. v eoaeer 14/ ENZ- March 1&{1969 R. w. 2N2 3,433,532

APPARATUS FOR EXGAVATING TUNNELS Filed June 12, 196 Sheet 3 of q FIG.3

. INVENTOR. ROBE RT W. ENZ

ATTORNEYS.

United States Patent 2 Claims ABSTRACT OF THE DISCLOSURE Apparatus for excavating tunnels, and particularly cylindrically shaped tunnels which includes a circular disc carrying a plurality of rock cutters thereon and adapted to be turned while being forced against the surface to be cut. The apparatus supports itself in the bore as it is cut, and provides a means for removing a cylindrical core of the material being excavated, and where the circular disc actually is comprised of two concentric portions which rotate in opposite directions to each other to provide an improved cutting action. The circular disc is mounted to a tubular frame which is telescopically carried by a second tubular frame relative to the second frame to provide flexibility and maneuverability to the circular disc.

This application is a continuation-in-part of my prior application, Ser. No. 418,676, now U.S. Patent No. 3,325,- 217.

Another object of the present invention is to provide a method of rock excavation of the sort described which employs mechanical power including electric, hydraulic, or other motor means for safe and continuous excavation.

A further object of the present invention is to provide an apparatus for rock excavation designed to carry out the improved method of the invention.

Apparatus for excavating tunnels through rock has previously been proposed which includes a circular disk carrying a multiplicity of rock cutters thereon and adapted to be turned while being forced against the rock face. This type of apparatus, however, has been deficient in necessitating very much labor, time, and power since it works for full-face operation, breaking off the entire face of the tunnel.

The present invention proposes to excavate tunnels by continuously digging the tunnel face in a manner so as to form an annular drift or trench of a definite radial width, leaving a cylindrical core of rock, and hauling out the latter rearwardly each time when the annular drift reaches an appropriate depth. Thus, according to the present invention, a tunnel is not bored out full-face but is bored only over an annular portion of the face leaving a cylindrical core, which breaks off under gravity into lumps or fragments depending upon the rock type. The lumps or fragments of rock thus formed are removed from the face with or without the aid of scraper means. It will be appreciated, therefore, that tunnels can be excavated efiiciently in a minimum of operation time and power and also with safety.

For a better understanding of the present invention, reference should be made to the accompanying drawings, in which:

FIG. 1 is a side elevational view, partially broken away, of an excavating apparatus embodying the present invention;

FIG. 2 is an axial cross-sectional elevation of the apparatus shown in FIG. 1;

FIG. 3 is a broken away cross-sectional end elevation of a modified two rotation counterboring embodiment of the invention; and

3,433,532 Patented Mar. 18, 1969 FIG. 4 is a cross-sectional view of the counter rotating heads of the embodiment of FIG. 3, taken on line 4-4- thereof.

Description will next be made on the essential parts of the rock excavating apparatus of the present invention with reference to FIG. 1, illustrating the external appearance of the apparatus and to FIG. 2, representing an axial cross-sectional elevation of same.

A first tubular frame 1-1A includes an annular rotary support 3 carrying a plurality of rock cutters 2 and drive means 4 for rotating the support 3. A plurality of hydraulic cylinders 5, mounted between outer cylindrical frame 37 and inner cylindrical frame 37a are secured to the forward section 1a of the first frame about its periphery for advancing the frame 1-1A with all of the members mounted thereon in the direction of excavation. Arranged concentrically with the first frame is a second tubular frame 6 which is a little larger in diameter and much reduced in length. The second frame 6 is connected with pistons 8, arranged within the respective cylinders 5, by way of rods 7.

The first frame 1-1A consists of two axially adjoining sections 1 and 1a and the forward section 1a is cylindrically shaped having the same diameter at its front and rear ends whereas the other or rearward frame section 1 is frustoconically having a diameter increasing rearwardly from the junction with the forward section 1a or having a taper angle of Also, mounted on the periphery of the second frame 6 are a plurality of hydraulic cylinders 10, as clearly shown in FIG. 2, which illustrates the frame 6 in trans verse cross section. Secured to pistons 28 arranged within the respective cylinders 10 are respective presser pads 11, which are radially movable. When the presser pads 11 are hydraulically forced radially outwardly against the resilience of spring means 30 so as to be firmly pressed against the wall of the excavated tunnel, substantial friction takes place between the wall surface and the presser pads 11 to hold the second frame 6 in position. When it is desired to displace the frame 6, hydraulic cylinders 10 are first de-energized to allow the presser pads 11 to be disengaged from the wall 103 of the excavated hole 100.

The hydraulic cylinders 5 accommodating respective pistons 8 are each secured sidewise to the forward section 1a of the first frame and carry at their top a support 14 on which rollers 9 are slidably supported for the purpose of rotating the annular support 3 with rock cutters 2 thereon while forcefully driving it in the direction of excavation.

Secured to the surface of the annular rotary support 3 opposite to its surface carrying cutters 2 is an internal gear 12 of a diameter R which is in mesh with pinions 13 adapted to be driven from the drive means 4. Thus, rotary support 3 is rotated with rotation of pinions 13.

The drive means 4 are secured to the first frame section 111 like hydraulic cylinders 5 and may take any suitable form such as electric or hydraulic motors. For both hydraulic and electric motors, it is necessary to provide a reduction gear 17 between each of the motors and associated pinion 12. Hydraulic motors are preferable to facilitate speed control.

The rock cutters 2 mounted on the annular rotary support 3 each take the form of a toothed wheel, for example, as shown in FIG. 2 and are arranged on a number of blocks 15. This is for the purpose of distributing the excavating load uniformly over all of the cutters 2 during excavation in order that the :face may be excavated uniformly over the entire area thereof as the rotary support 3 is driven to rotate. Some of the rock cutters, however, are mounted on the rotary support 3 so as to extend beyond either the inner or outer edge thereof as indicated at 2a and 2b, respectively, so that an annular bore hole or drift 100 may be formed which has a diameter slightly larger than that of the apparatus.

In order to enable use of rock cutters of the configuration conforming to the hardness, brittleness and other properties of the rock to be excavated, it is desirable to prepare blocks carrying cutters of different shapes ready for replacement.

Referring to FIG. 2, a hydraulic double-acting jack 20 including a cylinder and pistons accommodated therein is carried by a bracket arm 19 secured to the top portion of the first frame section 1 at its rear end and serves to press the rock core 101 downwardly to break it off. In order that the broken rock may readily be carried to the exterior, rollers 36 are mounted on the bottom portion of the frame section 1 with a roller or belt conveyor 18 joined to the rear end of the frame section at its bottom.

Although not shown in the drawings, it is to be understood that means are provided which feed water from a suitable water supply source through conduits and rotary parts to the face being excavated for the purpose of cooling the rock cutters 2, effecting lubrication of the respective rotary parts and flushing the rock fragments formed during excavation to the rear.

Description will next be made on the operation of the excavating apparatus of the present invention.

First, the first frame l-la is advanced until the rock cutters 2 thereon are brought into engagement with the rock face to be excavated. Then the pistons 8 with their rods 7 are actuated in the direction of the arrow in FIG. 2 and simultaneously the second frame 6 is displaced also in the direction of the arrow 38. Subsequently, hydraulic cylinders 10 arranged on the periphery of the second frame 6 are energized to force the presser pads 11 against the tunnel wall thereby to secure the second frame in position.

Following the above preliminary procedure, the hydraulic cylinders 31 mounted on the first frame 1 are controlled so as to hold the frame 1-1a at all times in axial alignment with the tunnel hole allowing the rollers 16 to slide along the wall thereof while on the other hand the hydraulic cylinders are energized to actuate respective pistons 8 and rods 7 in the direction of the arrow 39 whereby the hydraulic cylinders 5 and the first frame 1-1a connected integrally therewith are moved in a direction 38 opposite to that indicated by the arrow 39.

Then the drive means 4 are started to rotate the rotary support 3 with rock cutters 2 mounted thereon while pressing the latter against the rock face to form an annular hole 100 therein. During excavation its is desirable to feed water from an appropriate water supply source through conduit means and rotary parts of the apparatus to the face being excavated for the purpose of cooling the cutters 2, lubricating the respective rotary parts and flushing the rock fragments formed during excavation rearwardly from the face. As excavation proceeds, the pistons 8 are brought to the rear stroke end, but the rotation of the rotary support 3 need not be interrupted, and the hydraulic cylinders 10, arranged on the periphery of the second frame 6, are exhausted to allow the presser pads 11 to be disengaged from the wall of the tunnel hole under the bias of compression springs 30. Then the second frame 6 is moved in the direction of the arrow 38 as far as allowed by the stroke of the pistons 8 and the presser pads 11 are again firmly pressed against the wall of the tunnel hole to hold the second frame 6 in place. Now the entire apparatus is ready to repeat the excavating operation described hereinabove. In this manner, an annular bore 100 as illustrated in FIG. 1 is progressively formed leaving a cylindrical core of rock 101 inside of the first frame 1- 1a. In no time the cylindrical core 101 breaks off from the face under gravity at its base end and is hauled rearwardly or exteriorly of the tunnel by means of the conveyor .18. Where the cylindrical core 101 of rock is too hard to break off under gravity alone, the hydraulic jacks 20 should be operated to positively break off the core at its base end so that it may subsequently be carried out of the tunnel.

As will readily be noted, a straight tunnel can be excavated simply by repetition of the above procedure. To drive a curved tunnel substantially the same procedure can be employed except that the hydraulic cylinders 31 and pistons 32 should be operated in a different manner. In other words, any curved tunnel can be driven simply by varying the oil feed to the hydraulic cylinders 31 from each other between any two diametrically oppositely arranged ones depending upon the direction in which the tunnel is to be curved thereby to deviate the axes of the first and second frames from each other by an appropriate amount. In driving a curved tunnel, the entire apparatus must apparently be turned to a more or less extent in an appropriate direction in the interior of the tunnel excavated. Taking this into consideration, the rearward section 1 of the first frame is shaped frustoconically and some of the rock cutters are mounted on the rotary support 3 to extend radially beyond either the inner or outer edge thereof so that an annular bore may be formed which is slightly larger in size than the rotary support 3, as described hereinbefore.

FIGS. 3 and 4 represent a modified embodiment of the invention which comprises an annular outer crown, indicated generally by numeral 200, and an annular inner crown, indicated generally by numeral 202, each of which are rotatably supported by a first tubular frame 204. The frame 204 is telescoped with relation to a second tubular frame 206 in much the same manner defined with respect to the embodiments described above. Means to telescope (not shown) are contemplated to be provided. A presser pad, and stabilizing rollers, also not illustrated, are contemplated in this embodiment, too, however.

In essence, however, counter rotation of crowns 200 and 202 is achieved by inner and outer crown ring gears 200a and 202a respectively, each affixed or formed as an integral part of their respective crowns. A crown ring pinion 208 fixedly mounted to the end of a shaft 210 engages between both ring gears 200a and 202a. The shaft 210 is rotatably supported by frame 204 in bearings 210a and 21%. In order to provide a rotating drive to shaft 210, a gear 212 is fixedly mounted to the rear end thereof. A pinion gear 214 driven by a motor 216 engages in meshed relation with the gear 212. A flexible coupling 218 connects the output shaft of motor 212 to the pinion gear 214. In effect then a reduction is provided from the output speed of the motor through the use of pinion gear 214 and gear 212. A direct drive to shaft 210 could be utilized if a motor with sufficient capabilities were utilized.

Suitable rollers 220 rotatably journalled by the frame 204 support the rotation of crowns 200 and 202 as clearly shown in FIG. 4. Also, a suitable seal bearing 222 is provided between the outer opposed surfaces of the crowns 200 and 202, and fixedly mounted to the crown 200 to facilitate a sliding between these counter rotating surfaces and also to prevent the entry of foreign material into the gears and internal components of the apparatus. The bearing 222 may be made from a hardwood, or a suitable metal for example.

In the usual situation the outer exposed surfaces of each crown 200 and 202 mount a plurality of rock cutters 224 which cut out a path of slightly greater inner and outer diameter than either the crowns 200 and 202 or the frame 204. Although not shown in the drawings, it is to be understood that means are provided which feed water from a suitable water supply source through conduits and rotary parts to the face being excavated for the purpose of cooling the rock cutters 224, effecting lubrication of the respective rotary parts and flushing the rock fragments formed during excavation to the rear.

The operation of this counter rotating embodiment is as described for the other embodiments above. The crown 200 rotates in the direction of arrow 226 and crown 202 in the direction of arrow 228. The counter rotation gives a shearing cutting action by cutters 224 which in certain situations is much improved over that possible with the one way rotation of the entire head.

Although a few embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What is claimed is:

1. In an apparatus for excavating tunnels by forming a cylindrical core, breaking off that core and removing the same which includes a first tubular frame, and annular tool support rotatably mounted in concentric alignment on the first tubular frame, said annular tubular support comprising an annular outer crown and an annular inner crown each of substantially the same size and shape, and each rotatably mounted in concentric alignment on the first tubular frame, a plurality of cutters rotatably mounted in substantially equal numbers on the outer crown and inner crown of the tool support to define an annular cutting surface of slightly concaved configuration at the surface, and where the surface has a greater outer diameter and lesser inner diameter than the first tubular frame, and which forms a core upon rotation of the crowns, and means to rotate the respective crowns in opposite directions to each other about a common axis relative to the first tubular frame to effect the cutting action and formation of the core.

2. An apparatus according to claim 1 where a second tubular frame is arranged concentrically outside said first tubular frame in slidable and telescopic relationship therewith, means operatively attached to said second tubular frame to fix said second tubular frame in position by engaging the walls within a tunnel being excavated, means to control the telescopic relation of the first tubular frame relative to the second tubular frame, and a seal bearing provided between the outer opposed surfaces of the crowns and fixedly mounted to one of them to facilitate a sliding between these counter rotating surfaces and also to prevent the entry of foreign material into the internal components of the apparatus.

References Cited UNITED STATES PATENTS 1,511,957 10/ 1924 Freda 299-56 1,659,942 2/1928 Carlson 29986 X 2,919,121 12/ 1959 Ruth 2993 1 3,024,852 3/ 1962 Jewell -319 ERNEST R. PURSER, Primary Examiner.

US. Cl. X.R. 

